Firefox SHA-1 Certificate Errors and Antivirus Software

Starting January 1st 2016, Firefox began rejecting new SHA-1 SSL certificates that have been issued in the new year. For the majority of internet users, this change has gone unnoticed. However, Firefox users who have antivirus software installed that have begun generating unsecured connection to websites over HTTPS. The antivirus software sends Firefox a new SHA-1 certificate that is rejected by the browser. Mozilla has recommended upgrading to the latest version of Firefox to resolve seeing this issue and has recently published a blog post regarding this issue that you can read in the link below: